Simultaneous determination of alkylbenzenesulfonates and dialkyltetralinsulfonates in water by liquid chromatography

A previous method based upon Liquid Chromatography (HPLC) with fluorometric detection for determining linear alkylbenzenesulfonates (LAS) in aqueous environmental samples has been modified for extending it to the monitoring of dialkyltetralinsulfonates (DATS). DATS are reaction byproducts of LAS surfactant synthesis. 10, 100, 200, 1000 ml of respectively untreated sewage, treated one, riverwater and groundwater samples have been extracted by a 0.5-g Graphitized Carbon Black (GCB) cartridge. After sample extraction, co-extracted basic, neutral and weakly acidic compounds have been washed out by a formic acid containing solvent system. DATS and LAS have been then reextracted by passing through the cartridge a basified organic eluant mixture. After solvent removal and residue reconstitution by a suitable solvent system, the subfractionation of the analytes have been achieved by chromatographing them on a C-8 reverse-phase HPLC column. Recovery studies have shown that DATS have been quantitatively extracted by the GCB cartridge. By this procedure, the concentrations in water of DATS entering and leaving two sewage treatment plants in Rome have been monthly monitored over 1 year. With respect to LAS, the higher resistance to biodegradation of DATS has been demonstrated by comparative biodegradation tests. Analysis of a sewage-contaminated groundwater sample has shown that, although DATS are minor components in LAS formulations, the concentration of the former was even higher than that of the latter, with C₁₀ DATS being the most abundant species.     

Determination of chloroacetanilide herbicide metabolites in water using high-performance liquid chromatography-diode array detection and high-performance liquid chromatography/mass spectrometry

Analytical methods using high-performance liquid chromatography-diode array detection (HPLC-DAD) and high-performance liquid chromatography/mass spectrometry (HPLC/MS) were developed for the analysis of the following chloroacetanilide herbicide metabolites in water: alachlor ethanesulfonic acid (ESA); alachlor oxanilic acid; acetochlor ESA; acetochlor oxanilic acid; metolachlor ESA; and metolachlor oxanilic acid. Good precision and accuracy were demonstrated for both the HPLC-DAD and HPLC/MS methods in reagent water, surface water, and ground water. The average HPLC-DAD recoveries of the chloroacetanilide herbicide metabolites from water samples spiked at 0.25, 0.5 and 2.0 microg/l ranged from 84 to 112%, with relative standard deviations of 18% or less. The average HPLC/MS recoveries of the metabolites from water samples spiked at 0.05, 0.2 and 2.0 microg/l ranged from 81 to 118%, with relative standard deviations of 20% or less. The limit of quantitation (LOQ) for all metabolites using the HPLC-DAD method was 0.20 microg/l, whereas the LOQ using the HPLC/MS method was at 0.05 microg/l. These metabolite-determination methods are valuable for acquiring information about water quality and the fate and transport of the parent chloroacetanilide herbicides in water.     

海洋环境长寿命高性能混凝土的研究

系统研究了不同配合比参数对海洋环境混凝土性能的影响。试验结果表明,混凝土中掺入适量的粉煤灰、磨细矿渣粉可明显改善混凝土的工作性、提高混凝土的后期强度发展、提高混凝土的体积稳定性和抗氯离子渗透性。分析认为适合进行海洋环境长寿命高性能混凝土配制的配合比参数是:水胶比不低于0.30;采用混掺粉煤灰和磨细矿渣粉的胶凝材料体系,单掺粉煤灰掺量不高于30%,磨细矿渣粉不高于65%,两者混掺不高于70%;不宜采用单掺大量磨细矿渣粉的方式来配制混凝土。     

Analysis of mutagenic by-products produced by chlorination of humic substances by thin layer chromatography and high-performance liquid chromatography

Mutagenic by-products produced by chlorination of humic substances have been examined. Soil humic substances were obtained from a commercial source and also extracted from a local soil. Ether extracts recovered from chlorinated humic substances were subjected to thin layer chromatography (TLC) fractionation followed by high-performance liquid chromatography (HPLC) analysis. Results from TLC fractionation showed that chlorination of humic substances yielded polar and relatively non-polar mutagenic by-products. Polar mutagenic by-product(s) accounted for between 65 and 76% of the total mutagenic activity of the fractions separated by TLC, whereas the activity of relatively non-polar products accounted for only 14–23%. HPLC analysis shows that the chlorinated humic extracts give one and two mutagenic peaks for the polar and relatively non-polar TLC fractions, respectively. No qualitative difference in HPLC pattern of mutagenicity was seen among the humic substances used.     

利用气相色谱仪和硫化学发光检测器测定焦炉气制LNG工艺气中痕量硫化物

焦炉气制取LNG生产过程中需严格控制合成气中的硫含量,以期增加合成催化剂的使用寿命。采用气相色谱仪-硫化学发光检测器(GC-SCD)方法,测定了焦炉气制LNG过程中痕量形态硫化物及总硫含量,并结合实际,讨论了分析过程中需注意的问题。标准气校准,计算各种组分的检出限均低于10.00×10-9(体积分数),总硫含量33.00×10-9。6种含硫组分的标准曲线相关性均优于0.996。相对标准偏差(RSD,N=7)均小于7%。合成气样品测定过程中,在接近检出限的情况下,相对标准偏差小于12%。本方法可很好地满足工厂生产控制的需要。     

HPLC detection of linear alkylbenzenesulfonates surfactants (LAS) in marine sediments of the urban sewage area of Cortiou (Marseille,France)

An improved selective method for determining linear alkylbenzenesulfonates surfactants (LASs) in marine sediments using solid‐phase extraction and RP‐HPLC with UV detection is described. The complete analytical method is used on surface sediments from the creek of Cortiou, France. This site is affected by the sewage from the urban area of Marseille. The total LAS concentrations in the sediment range from 12.19?µg/g near the existing outlet to 0.47?µg/g beyond Maire Island. The flux of pollution provided by the outfall is preferentially oriented from east to west by the Liguro‐Provençal current. The significant values are mainly confined on a perimeter of 2.5?km around the outfall. The particule size observations concerning the sediments show that oxygenated sandy zones, where eliminating mechanisms (desorption, biodegradation) particularly occur, are mainly located on the Chèvres plateau and around Jarre, Plane and Riou Islands.     

高溶氧对闭合养殖系统中生物滤器功能的影响

研究了在封闭式循环养殖系统中,不同溶氧水平对生物滤器功能的影响及对大菱鲆Scophthalmusmaximus幼鱼生长的影响。结果表明:当水中溶氧(DO)为10.11 mg/L(B组)和11.91 mg/L(C组)时,生物滤器功能建立仅需要8 d时间,比对照组(A组,充空气)提前4 d;当水中总氨氮(TNH3-N)浓度为0.696 mg/L时,B2组(DO为12.11 mg/L±0.52 mg/L)24 h对TNH3-N的总去除率为89.60%,比对照A2组早6 h降低到0.2 mg/L以下;30 d的饲养结果表明,高溶氧可以提高大菱鲆幼鱼的增重率、特定生长率和饲料转化率;当水中TNH3-N浓度为0.700 mg/L(H组)时,在高溶氧下饲养的大菱鲆幼鱼各项生长指标均与对照D组无显著差异(P>0.05)。     

Determination of trace low-molecular-weight volatile polar organics in water by gas chromatography using distillation method

The distillation technique has been investigated as a means of concentrating in the distillate the low-molecular-weight volatile polar organic compounds such as alcohols, ketones, and aldehydes in aqueous solution. The volatility of these compounds relative to that of water was found to be a useful parameter in determining the concentration of the respective compounds in the distillate. By directly injecting the distillate onto a gas chromatographic column, low-molecular-weight volatile polar organics can be determined quantitatively at the ppb level. The relative standard deviation for the distillation technique is approximately 5% based on triplicate runs using an internal standard. This study shows that the distillation technique is a simple, unique, and efficient method of concentrating low-molecular-weight volatile polar organics at the ppb level for subsequent gas chromatographic analysis.     

Partitioning of marine antifoulants in the marine environment

The partitioning behaviour of the organic biocides, Irgarol 1051 and diuron and two inorganic biocides (copper and zinc) was investigated using six sediments of differing physico-chemical properties collected from unimpacted sites along the south coast of England. The kinetics of sorption and equilibrium partitioning between the sediments and seawater were investigated over a period of 20 days. Resulting organic carbon/water partition coefficients (log Koc) were related to suspended sediment concentration and ranged from 2.28 to 5.20 for diuron; and from 2.41 to 4.89 for Irgarol 1051. Sediment/water partition coefficients (log Kp) for copper and zinc varied from 2.46 to 5.08 l/kg and from 2.49 to 4.97 l/kg, respectively. Kinetic data indicated that there were significant interactions between the dissolved and particulate phases at the start of the experiments, just after mixing. This is thought to be a result of redistribution of organic carbon between the two phases.     

超声辅助固相萃取高效液相色谱法快速分离测定牛奶中的硫氰酸钠

建立超声辅助固相萃取牛奶中硫氰酸钠的方法,高效液相色谱法分离和测定牛奶中的硫氰酸钠。研究讨论和优化试验条件,包括蛋白沉淀剂的选择、超声时间、固相萃取柱的类型、色谱条件。乙腈作为蛋白沉淀剂,超声10 min,选择C18作为固相萃取柱。硫氰酸钠的精密度和回收率分别为2.38%⁶.70%,88.41%6.70%,88.41%¹05.89%。此方法中硫氰酸钠检出限是0.014 mg·kg-1。     

Occurrence and fate of linear and branched alkylbenzenesulfonates and their metabolites in surface waters in the Philippines

Laguna de Bay in the Philippines is one of the largest freshwater lakes in Asia and is considered a primary source of drinking water, but also receives daily discharges of effluent from both domestic and industrial activities. Branched alkylbenzenesulfonates (ABS), which were banned in Europe and withdrawn from the market in the U.S. since the mid-1960s, but not in Southeast Asia, and linear alkylbenzenesulfonates (LAS) are anionic surfactants used in detergent formulations and are therefore main components of effluent discharges. The presence of both LAS and ABS in several water streams in the catchment area of Laguna de Bay was determined using liquid chromatography-mass spectrometry (LC-MS). The concentration levels of LAS (1.2-73 and 2.2-102 microg l(-1)) and ABS (1.1-75 and 1-66 microg l(-1)) in some tributaries of Laguna de Bay and its outlet (Pasig River) to Manila Bay were assessed in December 1999 and March 2000, respectively. The LAS/ABS ratio was calculated as an indication of the extent of the distribution and fate of these surfactants in the surface water. The nearer the location to the metropolitan area of Manila, the higher the levels of LAS and ABS detected in the waters. Moreover, the extent of biodegradation was investigated by monitoring their alkyl homologue distribution and the presence of sulfophenylcarboxylate (SPC) metabolites. Similarly, differences in the levels of SPC and the homologues were apparent at the different sampling points. Presumably, even the quite recalcitrant ABS form SPCs under the conditions present in Southeast Asia. Since wastewater treatment facilities are not well established in developing countries like the Philippines, the call for the use of environmentally friendly chemicals is of even higher significance.     

海岸工程对海洋环境的影响

总结分析了海岸工程对海洋环境的具体影响,包括改变海洋水文动力环境,影响海水水质,破坏近岸海域生态环境等,对环境保护部门进行海洋环境影响因子识别有着重要的意义和参考价值。     

Initial studies on the use of high-performance liquid chromatography for the rapid assessment of sewage treatment efficiency

High-performance liquid chromatography (HPLC) techniques suitable for the rapid analysis of some dissolved organic constituents (uric acid, creatine, creatinine, amino acids etc.) of sewage are presented. The techniques are applied to full scale field trial assessment of the degradation potentials of an activated sludge and a biological filter sewage works. The results obtained for the fate of specific polar low-molecular weight constituents are compared with concurrently obtained dissolved and total BOD₅, COD, ammonium and total oxidised nitrogen data. The data suggests that HPLC techniques may offer an alternative to BOD₅, COD analyses and give an insight into the fundamental removal processes occurring during primary and secondary sewage treatment.     

The use of reverse phase liquid chromatography for studying trace metal-organic associations in natural waters

Reverse-phase liquid chromatography was employed for the separation of natural water organics into fractions of varying polarity. Concomitant metals were monitored by electrothermal atomization atomic absorption spectrophotometry.     

海工高性能混凝土回弹测强研究——采用高强回弹仪建立海工高性能混凝土测强曲线

施工现场高性能混凝土结构无损检测强度反映实际强度准确性的矛盾日益凸显。尤其对海工高性能混凝土而言,其回弹推定强度往往比结构实际强度偏低很多,且没有地区或专用曲线采用。该研究通过采集不同强度等级海工高性能混凝土的试验数据、分析处理、归纳得出回弹值与抗压强度之间的相关关系曲线。经计算其平均相对误差和相对标准差均优于规范关于专用回弹曲线的规定。找到了合理解决海工高性能混凝土构件质量现场检验的方法,可以快速、准确、合理的评价现场构件的施工质量,同时可节省人力、物力和财力,这将给施工带来极大的方便。经过验证,其具有普遍的适用性,将产生良好的社会效益与经济效益,为以后建立全国统一的海工高性能混凝土回弹测强通用曲线提供必要的素材。     

催化动力光度比色法测定痕量银

ＧＢ５７４９—８５《生活饮用水卫生标准》对饮用水中银的含量做出了规定,并在ＧＢ５７５０—８５《生活饮用水标准检验法》中提出了对银的检验法即原子吸收分光光度法。该法费时、费力,操作复杂,检测成本较高且银的检出率很低。现推荐采用催化动力———光度比色法进...     

Comparative studies on trace metal levels in marine biota I. Mercury in marine organisms from western Italian coast,the strait of Gibraltar and the North Sea

The mercury level has been determined in the edible part of 36 marine species (867 specimens) caught from 1975 to 1976 mainly close to the Western Italian coast, the Strait of Gibraltar and in some selected regions of the North Sea. Sample pretreatment was performed after careful preparation by nitric acid pressure decomposition of frozen stored subsamples using up to 2.5 g fresh weight (FW). The analytical method was automated cold vapour atomic absorption spectrophotometry after preconcentration on silver wool. Accuracy and precision of the method was checked by interlaboratory intercomparisons and intralaboratory test measurements of repeatability and also the use of Standard Reference Materials. The total mercury (HgT) values obtained ranged from 20 μg/kg FW to ?2,000 μg/kg Fresh weight for the Mediterranean Sea and for some pelagic species showed significantly elevated mercury values compared with organisms from the Atlantic and North Sea. For benthic organisms, however, probably due to dominating local influences, a similar behaviour has not been observed. Evaluation of body weight/mercury concentration ratios showed significant correlations for several species differing between distinct locations.     

石墨炉原子吸收光谱法测定水中痕量铊

建立了直接测定水中铊的无灰化石墨炉原子吸收光谱法.样品经过前处理浓缩后,在优化的仪器工作参数下,该方法对铊的检出限为0.04μg/L,回收率在80%～110%之间,相对标准偏差(n=6)为1.3%～4.56%.所建立的分析方法准确、快速,适用于地表水、生活饮用水、矿泉水中痕量铊的检测,具有一定的推广应用价值.     

Mineralization of alkylbenzenesulfonates in water by means of contact glow discharge electrolysis

Mineralization of aqueous alkylbenzenesulfonates (ABS) was investigated by means of contact glow discharge electrolysis (CGDE). Toluenesulfonic and dodecylbenzenesulfonic acids in a neutral phosphate buffer solution were smoothly degraded and eventually converted to inorganic carbon and sulfate ion when CGDE was conducted under the applied DC voltage of 500 V and current of ca. 90 mA. As the intermediate products, some phenolic compounds were detected as well as carboxylic acids such as oxalate, formate and so on. It was demonstrated that the decay of ABS followed the first-order rate law. Based on the detailed analysis of the hydroxylation products and kinetic consideration, it was assumed that hydroxyl radicals would play a crucial role in the oxidative degradation of aqueous ABS. The features of CGDE as a tool for the removal of organic pollutants in water were discussed in comparison with other physicochemical methods.